Television production, mass media, and Internet technology companies are turning their attention to the emerging medium of Interactive TV. Interactive TV uses technologies from the Internet to deliver interactive content in the form of graphical and informational elements on the same screen as a video program. Once transmitted over the air or via telephone wires and cables, the interactive content is televised on top of video programming viewed on traditional TV sets, computers, and on other video-ready digital products
To the end user or viewer, the interactive content appears as graphical and informational images on the screen overlaying a video broadcast. Often these images are opaque and cover the video broadcast in part, or they are transparent or semi-transparent. Specific reoccurring interactive content images include icons, banners, labels, menus, information about the program, data one can print, open text fields in which one can insert an email address, or forms to fill out in order to buy a product. If the producer has done an adequate job, the interactive content will be relevant to the television programming presented with it.
To navigate and participate in such interactive television broadcasts, viewers can use the buttons on the remote control, type commands or words with a wireless keyboard on certain systems, or use the mouse if viewing interactive TV via a computer with a TV tuner card. Depending upon the network, the viewer's set-top box will receive an electronic programming guide (EPG); a special TV-online service containing links to local information; or applications like email, games, home banking, and community message boards. The viewer's responses to the interactive content are transferred by the set-top box as signals back to the broadcast station. Where the viewer's set-top box is connected to the broadcaster over a cable TV network, the viewer's response signals are returned over a duplex commumication path of the cable TV network. Where the viewer 's set-top box is connected to the broadcaster over a wireless link, the viewer's response signals can be returned over a duplex commumication path of the wireless link or alternately they may be returned via another medium, such as the public switched telephone network.
A problem exists in how to effectively control the Digital TV Studio to organize the interactive content and input its data to an MPEG-2 data injector, which embeds the interactive content in an MPEG-2 Transport Stream to be sent to the end user. Today's systems generally require the broadcaster to preview the entire length of each program before the program is transmitted, in order to index the program with sequential code data representing the interactive content to be presented in the program. Such systems generally require separate sub-systems to watch the program and lack the capability to monitor the end user's usage of the interactive content.